Ditto

Ditto is a niche yet potent revenge killer, leveraging its Imposter ability to quickly reverse sweeps, which would otherwise pose a significant threat to its team. Choice Scarf is both Ditto's biggest strength and Achilles' heel, allowing it to outspeed the Pokemon it copies; however, it is limited to choosing one move, allowing its opponent to respond accordingly by switching to a check. Partially due to being Choice-locked, Ditto struggles against opposing defensive Terastallization, where foes may gain a resistance or immunity to Ditto's moves and fire back with a powerful attack. However, due to Ditto’s lack of any defensive utility and being somewhat situational as well as matchup dependent, Ditto is not a common Pokemon.